Improved urine measurement device and method

ABSTRACT

A urine handling system capsule ( 105 ) for releasing an oil mixture in the lumen of a urine handling system, the capsule ( 105 ) comprising a capsule wall defining a space filled with an oil mixture, wherein the oil mixture comprises 90-100% of an oil selected from the group consisting of silicone fluids and mineral oils or a mixture thereof, and having a viscosity of at most 600 cSt, and wherein the capsule wall is made of a water-soluble material. A urine measurement system ( 101 ) comprising an oil mixture arranged in the luminal space of the measurement system. A method for inhibiting impairment of functionality and measurement accuracy in a urine measurement system comprising applying an oil mixture to the inner surfaces of the urine measurement system. Use of an oil mixture in treatment of luminal surfaces of a urine handling system.

TECHNICAL FIELD

The present invention relates to a device and a method for measurementof urine production of a patient wearing a catheter. More specificallyit relates to devices and methods for increasing operational time andaccuracy of such a device.

BACKGROUND ART

Electronic urine measurement systems are known in the art.

WO 2010/149708 A1 discloses a urine measurement device for measuringurine production of a patient having a urine catheter. The device usescapacitive measurements from electrodes arranged close to a selfemptying measurement chamber to calculate the urine level in themeasurement chamber.

U.S. Pat. No. 3,919,455 describes a device comprising a siphon chamberfor the urine with a self emptying function, and wherein the urinevolume is measured with the aid of an optic and/or electric sensor. Whenthe urine level in the siphon chamber increases, the capacitance betweentwo electrodes in the walls of the siphon chamber changes. In this way asignal is created that corresponds to the amount of urine in the siphonchamber. See e.g. FIG. 4 and column 4 lines 34 to 52.

US20110146680A1 discloses a method for manufacturing a silicone catheterwherein the catheter is immersed in oil before it is immersed in aliquid comprising the antimicrobial substance chlorhexidine gluconate inorder to make the chlorhexidine gluconate better adhere to the catheter.

SUMMARY OF THE INVENTION

Urine meter systems in general are depending on a connection to a urinecatheter in order to get access to the urine-bladder and drain urinefrom the bladder through a tubing system. The urine is led through ameasuring unit and then collected in a collection bag.

Urinary Tract Infection (UTI) is the most common nosocomial infectionwithin the healthcare system today. The UTI extends length of stay,increase costs and contributes to an additional risk to the patients'health status. It's usually related to the installation of said urinecatheter. It's revealed through clinical research that the risk of UTIincreases by 10% each day the catheter stays in the urinary tract.Bacteria has either their entrance from the outside of the body (64%) orfrom the very inside (36%).

The inventors have realised, with the aid of literature studies that inin-vitro system bacterial colonisation generates a bio film that becomesmineralised (encrustation). In sterile urine, the development ofencrustation has been shown to be dependent on urinary properties suchas pH and ionic strength as well as on the biomaterial hydrophobicproperties. Urine is generally free from bacteria and thus it is thechemistry of the urine in a measuring and/or collecting environment thatdominates the variables. In infected urine, enzyme urease produced byadhered bacteria hydrolyses the urea to produce ammonia. This elevatesthe urine pH, a condition that favours the precipitation of magnesiumand calcium in the form of struvite and hydroxyapatite (HA). Theseminerals are two major component of encrustation.

Said bio-film and related risk of nosocomial UTIs are not visible to thehuman naked eye, at least not in the early stages of formation.

Sensor arrangement, signal processing, and signal interpretation methodsof signals coming from a capacitive sensor system of a urine measurementsystem for measuring the urine production of a patient having a urinecatheter, may all suffer from harder measuring conditions that arelikely to arise over time during prolonged use of such a measuringsystem.

The inventors have presented the idea that surface degeneration mayimpair function of a capacitive measuring system and may cause adysfunction of the siphon portion of the self-emptying chamber. Theyhave conducted experiments around how the presence of a purpose selectedoil in the measurement chamber of the siphon system prolongs operationallife of the same. They have also suggested that priming of luminalsurfaces of the system may be achieved by self-priming with the aid ofthe urine flowing through the system.

The present invention is providing a device and a method for improvingthe above mentioned inconveniences by the step(s) of applying a lowviscosity oil to the inner surfaces of a urine handling system, with thepurpose of arriving at a urine handling system with sustained functionalreliability and sustained measurement accuracy, in particular duringprolonged use. The effect may be due to the oil influencing factorsaffecting bacterial growth and bio-film formation. The effect may alsocome from other mechanisms or from a synergetic effect not yet fullyunderstood.

The present invention discloses a urine handling system of a measurementtype having a capacitive sensor system working together with a selfemptying measurement chamber and being provided with a capsule of amaterial that will disintegrate when coming into contact with urine,e.g. a water soluble material. The capsule is initially filled with apurpose selected oil and when the capsule disintegrates the oil istransported with the aid of the urine flow to become applied to thosesurfaces of the urine handling system that becomes exposed to urine.

The invention is particularly useful in systems that use electronicmethods for measuring the amount of urine passing through the system,for example capacitive measurement methods. It will also provide anadvantage in systems using self emptying chamber(s) to handle urinemeasurements. Tests have shown that the self emptying function of suchchambers will continue to function reliably for several days, whilewithin a system without the solution of the present invention,functionality may be compromised as soon as after 24 hours.

A urine measurement system according to the present invention thuscomprises a well defined measurement chamber for temporarily collectingan amount of urine to measure. The chamber may be of a self emptyingsiphoning type, that is, the chamber, when it becomes full, emptiesitself by means of siphoning technique.

Thus, according to a first aspect of the present invention there isprovided a urine handling system capsule for releasing an oil mixture inthe lumen of a urine handling system, the capsule comprises a capsulewall defining a space filled with an oil mixture, wherein the oilmixture comprises 90-100% of an oil selected from the group consistingof silicone fluids and mineral oils or a mixture thereof, and having aviscosity of at most 600 cSt, and wherein the capsule wall is made of awater-soluble material.

The capsule wherein the water-soluble material is selected from thegroup consisting of hydroxypropyl methylcellulose and polyvinyl alcohol(PVOH) or a mixture thereof.

The capsule wherein the oil mixture is selected from the group ofsilicone fluids.

The capsule wherein the oil mixture is selected from the group of linearpolydimethylsiloxanes.

The capsule wherein the viscosity of the oil is in the interval of 200to 600 cSt.

The capsule wherein the viscosity of the oil is in the interval of 300to 400 cSt.

The capsule wherein the viscosity of the oil is in the interval of 345to 355 cSt.

The capsule wherein the viscosity of the oil is about 350 cSt.

According to a second aspect of the present invention there is provideda urine measurement system comprising a urine measurement chamber,wherein the urine measurement system comprises an electronic measurementsystem comprising electrodes arranged outside but close to saidmeasurement chamber to measure changing capacitance values as urinelevel inside the chamber increases and/or the urine measurement chambercomprises a self-emptying siphoning arrangement arranged to empty itselfby means of siphoning technique, wherein an oil mixture is arranged inthe luminal space of the urine measurement system, wherein the oilmixture comprises 90-100% of an oil selected from the group consistingof silicone fluids and mineral oils or a mixture thereof, and having aviscosity of at most 600 cSt.

The urine measurement system, wherein the viscosity of the oil is in theinterval of 200 to 600 cSt.

The urine measurement system, wherein the viscosity of the oil is in theinterval of 300 to 400 cSt.

The urine measurement system, wherein the viscosity of the oil is in theinterval of 345 to 355 cSt.

The urine measurement system, wherein the viscosity of the oil is about350 cSt.

The urine measurement system, wherein the capsule mentioned above isarranged in the luminal space of the measurement system.

The urine measurement system, wherein the capsule is arranged upstreamof the measurement chamber or in an upstream portion of the measurementchamber. The urine measurement system, wherein the capsule and possibleparts of the capsule wall in early stages of disintegration is preventedfrom entering a measurement portion of the measurement chamber by agrate.

The urine measurement system wherein the grate is made of a metal orpolymer material.

The urine measurement system, wherein the material of the measurementchamber is selected from a group consisting of polymer materials.

The urine measurement system, wherein the material of the measurementchamber is selected from a group consisting of glass materials.

The urine measurement system, wherein the material of the measurementchamber is selected from a group of materials having lipophilicproperties.

According to a third aspect of the present invention there is provided amethod for inhibiting impairment of functionality and measurementaccuracy in a urine measurement system having inner surfaces coming intocontact with urine, the method comprising the following steps:

-   -   applying an oil mixture to the inner surfaces of the urine        measurement system by self-priming with aid of the urine.

The method wherein the method further comprises the step spreading theoil mixture on top of the urine.

The method wherein the urine takes with it the oil mixture when thelevel of urine in the measurement system increases during filling of themeasurement system and thereby the oil mixture is brought in contactwith and adheres to the inner surfaces.

The method wherein the oil mixture comprises 90-100% of an oil selectedfrom a group consisting of silicone fluids, and mineral oils, or from amixture thereof.

The method wherein the oil has a viscosity of at most 600 cSt.

The method wherein the oil has a viscosity in the interval of 200 to 600cSt.

The method wherein the oil has a viscosity in the interval of 300 to 400cSt.

The method wherein the oil has a viscosity in the interval of to 355cSt.

The method wherein the oil has a viscosity of about 350 cSt.

The method wherein the oil mixture is applied by connecting a patient'surinary catheter with the urine measurement system mentioned aboveprovided with the capsule mentioned above.

According to a fourth aspect of the present invention there is provideda use of an oil mixture in treatment of luminal surfaces of a urinehandling system, wherein the oil mixture comprises 90-100% of an oilselected from the group consisting of silicone fluids and mineral oilsor a mixture thereof, and having a viscosity of at most 600 cSt.

The above use, wherein the viscosity is in the interval of 200 to 600cSt.

The above use, wherein the viscosity is in the interval of 300 to 400cSt.

The above use, wherein the viscosity is in the interval of 345 to 355cSt.

The above use, wherein the viscosity is in the interval of 345 to 355cSt.

The above use, wherein the viscosity is about 350 cSt.

The above use, wherein the oil mixture is an oil mixture void ofantimicrobial agent.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further explained with the aid of one or moreembodiments of the invention in conjunction with the accompanyingdrawings of which:

FIG. 1 a is a front view of a measurement chamber of a urine handlingsystem.

FIG. 1 b is view of the measurement chamber of FIG. 1 a wherein a frontwall is removed exposing the inner structure including capsule/oil pillarrangement and grate arrangement.

DETAILED DESCRIPTION Definitions

In the context of the present invention the following terms and phraseswill be used having the following meanings:

A “urine handling system” denotes a system for handling of urineemanating from a human patient involved in a care situation, includingbut not limited to, a nursing situation and a treatment situation.

A “urine measurement system” denotes a system designed to measure theamount of urine emanating from a human patient involved in a caresituation, including but not limited to, a nursing situation and atreatment situation.

The term “silicone fluid” is intended to include silicone oils such assilicone esters or other liquid silicone compounds with the generalformula:

where each R can be an aliphatic group such as an alkyl group, forexample a methyl, ethyl or propyl radical or alkoxy group or a phenylgroup, or combinations thereof; andwhere x has a value of from about 0 to about 10,000, preferably fromabout 1 to about 200, and most preferably from about 10 to about 125.

The problem

Urine is a body liquid that may be very aggressive on manmade surfaces,in particular on surfaces inside a urine measurement system. The urinemeasurement system according to the invention may be a closed systemthat comprises a tubing system connected to a patient's catheter, ameasurement chamber and a collection bag. The urine measurement systemis located outside the body of a patient. The tubing system leads theurine from the urine bladder to the measurement chamber where acapacitive, contact-less sensor system senses the signals through thewall of the measurement chamber, and thereof calculates the volume. Thechamber wall is preferably of a rigid polymeric material, easilyobtained in medical equipment grades. The urine is preferably collectedin a collection bag after it has been measured. Such a collection bag ispreferably made of a flexible polymeric material, and has a volumeconsiderably larger than the volume of the measurement chamber.

The measurement chamber is preferably devised to self-empty at a certainvolume around 15-20 ml. The challenge in said self-emptying measurementchamber is to handle the effects of degenerative process compromisingthe electric and physical properties of the delicate surfaces of themeasurement chamber caused by the urine over time.

Thus, and as also mentioned above, the inventor has realised, and alsoexperience, that within an unforeseeable amount of time there is adecrease of signal through the measurement chamber wall that seems to becaused by a bio film formation on the surface(s) corresponding to wherethe sensors are arranged. There seems to be a considerable risk of adegeneration of the delicate surfaces within the region of theself-emptying system which may lead to a dysfunction of theself-emptying mechanism.

One solution to the problem would be to replace the chamber when signsof dysfunction are noticeable. However, it would be an advantage if thiscould be avoided, since it requires more resources.

The solution

Now turning to FIGS. 1 a and 1 b, the present invention teaches to applya substance to the surfaces of the urine measurement system to improvesustained measurement functionality and accuracy.

If a urine measurement system provided with a measurement chamber 101comprising a siphoning self-emptying arrangement begins to executepremature emptying sequences, it is likely that surface(s) of themeasurement chamber 101 critical to initiation of the self-emptyingsequence, has become compromised. The solution involves arranging an oilreleasing device 105 early in the flow path of the urine measurementsystem, and to let said oil releasing device 105 release oil into thesystem for adhering to the luminal surfaces of the system. Subsequent torelease the urine, as being a watery, oil repellant fluid, aids indispersing the oil, which oil gets on top of the urine, and during afilling phase of the measurement chamber, takes with it the oil, whichoil adheres to the luminal surfaces in need thereof.

It is realised by the skilled reader that this measure of providing anoil releasing device would improve not only a urine measurement system,but any urine handling system liable or susceptible to degradation overtime.

The present invention relates to a method for improving sustainedfunctionality and measurement accuracy in a urine measurement systemhaving inner surfaces coming into contact with urine, the methodcomprising the following step(s):

-   -   applying an oil mixture to the inner surfaces of the urine        measurement system.

By improving sustained functionality and measurement accuracy,impairment of functionality and measurement accuracy is inhibited.

Thus, the present invention relates to a method for inhibitingimpairment of functionality and measurement accuracy in a urinemeasurement system having inner surfaces coming into contact with urine,the method comprising the following step(s):

-   -   applying an oil mixture to the inner surfaces of the urine        measurement system.

The oil mixture is preferably applied to inner surfaces of the urinemeasurement system by self-priming with aid of the urine. The oilmixture may be applied to inner surfaces of the urine measurement systemby self-priming with aid of the urine flowing through the system.

The method may comprise the step spreading the oil mixture on top of theurine. This step may be performed before the step applying an oilmixture to the inner surfaces of the urine measurement system.

In one embodiment, the oil mixture is applied to the inner surfaces ofthe urine measurement system when the level of urine in the urinemeasurement system increases. This may be combined with the stepspreading the oil mixture on top of the urine. This is a way to achieveself-priming of the inner surfaces with the oil mixture aided by theurine.

In one embodiment, the urine takes with it the oil mixture when thelevel of urine in the measurement system increases during filling of themeasurement system and thereby the oil mixture is brought in contactwith and adheres to the inner surfaces.

The urine may take with it the oil mixture when the level of urine in ameasurement chamber of the measurement system increases during fillingof the measurement chamber and thereby the oil mixture is brought incontact with and adheres to the inner surfaces.

The method may comprise the step adhering the oil mixture to the innersurfaces. This step may be performed in combination with and after thestep spreading the oil mixture on top of the urine. This is a way toachieve self-priming of the inner surfaces with the oil mixture aided bythe urine.

The oil mixture may be spread on top of the urine, brought into contactwith the inner surfaces by the urine and adhere to the inner surfaces.Thereby, the oil mixture is applied to the inner surfaces of the urinemeasurement system by self-priming. The urine may take with it the oilmixture when the level of urine in the measurement system increasesduring filling of the measurement system and thereby the oil mixture isbrought in contact with and adheres to the inner surfaces.

The oil mixture may be applied to the inner surfaces of the urinemeasurement system by providing a water-soluble capsule in the urinehandling system. The water-soluble capsule may be provided in the urinehandling system upstream of a measurement portion and a siphoningportion of a urine measurement chamber of the system.

When the oil mixture has been released the oil mixture is spread on topof the urine, since urine is a watery and oil repellent fluid. The oilmixture forms a layer on top of the urine. When the amount of urine inthe urine measurement system and thus the level of urine in the urinemeasurement system increases the oil mixture that is floating on top ofthe urine is brought in contact with the inner surfaces of the urinemeasurement system. The oil mixture adheres to the inner surfaces and isapplied to the inner surfaces. Thereby, the oil mixture is applied tothe inner surfaces before the urine reaches higher levels of the innersurfaces. Thus, the oil mixture prevents or at least makes it moredifficult for the urine to come into direct contact with the innersurfaces of the urine measurement system. The oil mixture is moved bythe urine when the level of urine increases and thereby the oil mixtureis applied to the inner surfaces of the urine measurement system justbefore the urine reaches a higher level in the urine measurement system.Thus, the inner surfaces are freshly coated with the oil mixture whenthe urine reaches the inner surfaces. After emptying of the urinemeasurement system, the oil mixture is applied again on the innersurfaces before the urine reaches the inner surfaces. Thus, the innersurfaces are always freshly coated with the oil mixture when urinereaches the inner surfaces. Thereby, an improved resistance againstdegeneration of the inner surfaces of the urine measurement system.Consequently, the functionality of the urine measurement system, such asthe functionality of the siphoning self-emptying arrangement, isimproved. For example is the degradation of the surfaces of thesiphoning self-emptying arrangement inhibited and thus the siphoningeffect is maintained. The functionality over time is improved andimpairment of the functionality is inhibited. Also the measurementaccuracy of the urine measurement system, such as the measurementaccuracy of the capacitive measurement system, is improved. For exampleis the degradation of the surfaces of the wall of the measurementchamber through which the capacitive measurement system senses signalsinhibited and thus the sensing ability is maintained. The measurementaccuracy over time is improved and impairment of the measurementaccuracy is inhibited.

The urine measurement system may comprise a urine measurement chamber.The urine measurement system may comprise electrodes arranged outsidebut close to the measurement chamber. The electrodes may be arranged tomeasure changing capacitance values as urine level inside the chamberincreases. The electrodes may be arranged on the outside of themeasurement chamber. The electrodes may be arranged on the outer surfaceof the measurement chamber. The electrodes may be integrated in themeasurement chamber. The electrodes may be integrated in the measurementchamber on the outside of the measurement chamber.

In one embodiment, the present invention relates to a urine measurementsystem comprising a urine measurement chamber, wherein the urinemeasurement system comprises an electronic measurement system comprisingelectrodes arranged outside but close to said measurement chamber tomeasure changing capacitance values as urine level inside the chamberincreases, wherein an oil mixture is arranged in the luminal space ofthe urine measurement system, wherein the oil mixture comprises 90-100%of an oil selected from the group consisting of silicone fluids andmineral oils or a mixture thereof, and having a viscosity of at most 600cSt.

In one embodiment, the present invention relates to a urine measurementsystem comprising a urine measurement chamber, wherein the urinemeasurement chamber comprises a self-emptying siphoning arrangementarranged to empty itself by means of siphoning technique, wherein an oilmixture is arranged in the luminal space of the urine measurementsystem, wherein the oil mixture comprises 90-100% of an oil selectedfrom the group consisting of silicone fluids and mineral oils or amixture thereof, and having a viscosity of at most 600 cSt. Theself-emptying siphoning arrangement may be arranged to empty itself bymeans of siphoning technique when a certain volume of urine is presentin the urine measurement chamber.

In one embodiment, the present invention relates to a urine measurementsystem comprising a urine measurement chamber and an electronicmeasurement system comprising electrodes arranged outside but close tosaid measurement chamber to measure changing capacitance values as urinelevel inside the chamber increases, wherein the capsule of the presentinvention is arranged in the luminal space of the measurement system.

In one embodiment, the present invention relates to a urine measurementsystem comprising a urine measurement chamber, wherein the urinemeasurement chamber comprises a self-emptying siphoning arrangementarranged to empty itself by means of siphoning technique, wherein thecapsule of the present invention is arranged in the luminal space of themeasurement system. The self-emptying siphoning arrangement may bearranged to empty itself by means of siphoning technique when a certainvolume of urine is present in the urine measurement chamber.

In one embodiment the present invention relates to a urine measurementsystem comprising a urine measurement chamber, wherein the urinemeasurement system comprises an electronic measurement system comprisingelectrodes arranged outside but close to said measurement chamber tomeasure changing capacitance values as urine level inside the chamberincreases and the urine measurement chamber comprises a self-emptyingsiphoning arrangement arranged to empty itself by means of siphoningtechnique, wherein the capsule of the present invention is arranged inthe luminal space of the measurement system.

Capsule

The oil releasing device is preferably implemented as a capsule 105comprising a capsule wall made of a water-soluble material. The capsuleencapsulates an amount of oil. The capsule is preferably of a shapeselected from the group of cylindrical, cylindrical with hemisphericalends, spherical, oval, elliptical or of a shape rounded cubic or tablet,or of any shape suitable to the purpose.

The material of the capsule wall is a water-soluble material, preferablyone that disintegrates in a few minutes when exposed to urine flow. Onepreferred material of the capsule wall is polyvinyl alcohol (PVOH). Mostpreferred, however, the material of the capsule wall is hydroxypropylmethylcellulose, such as for example the material of LICAPS capsulesfrom CAPSUGEL—www.capsuqel.com. One particular advantage of PVOH is avery quick release of the oil because of fast disintegration. Oneadvantage of hydroxypropyl methylcellulose is its stability whichfacilitates handling, storage and transportation.

In one embodiment, the material of the capsule wall disintegrates withinone hour. Thereby, the material of the capsule wall is disintegratedwithin one hour after is has been exposed to urine. This has theadvantage that the oil mixture in the capsule is rapidly released andthe thus the protection of the inner surfaces of the urine handlingsystem is rapidly established. The material of the capsule wall maydisintegrate within 30 minutes after exposure to urine, such as within15 minutes, such as within 10 minutes, such as within about 5 minutes.The material of the capsule wall may disintegrate within a few minutes.The material of the capsule wall may disintegrate within a few minutesafter exposure to urine. The material of the capsule wall is preferablytotally disintegrated within the above specified time intervals.

In addition to improved measurement accuracy and operational life of themeasurement chamber, the capsule allows that the oil, as an activeingredient, is inactive during shelf life and activated first in theclinical setting.

The capsule provides a convenient way of storing and handling the oilmixture during transport and storage of a urine measurement system. Thecapsule also provides a convenient way of activating the protection ofthe inner surfaces of the urine measurement system in the clinicalsituation, i.e. when the urine measurement system is to be put inoperation. The capsule can be stored in the urine measurement system orseparately up until use of the urine measurement system. Since the oilmixture not is applied to the inner surfaces of the urine measurementbefore use of the urine measurement system, the protection of the oilmixture provided to the inner surfaces is not damaged or deterioratedbefore use of the urine measurement system. If not stored in the urinemeasurement system, the capsule is inserted in the urine measurementsystem before use. When the urine measurement is to put into use, theurine that is entering the urine measurement system dissolves thewater-soluble material of the capsule wall releasing the oil mixture.The oil mixture is transported with the urine into the measurementchamber and the oil mixture is thereby distributed into the measurementchamber. The water-soluble material is preferably disintegrated in a fewminutes when exposed to urine in order to release the oil mixturerapidly and to rapidly establish the application of the oil mixture onthe inner surfaces of the urine measurement surface aided by the urineas described above. Thereby, the protection of the inner surfaces of theurine measurement system is rapidly established.

To prevent the capsule from interfering with urine flow in themeasurement chamber it is advantageous to provide a grate 110 or similararrangement to prevent early, non dissolved fragments of the capsule toclog the flow of urine. It is also advantages to provide such a grate toconfine the capsule during transport and pre-use to an upper portion ofthe measurement chamber.

Thus, the grate 110 is arranged to prevent pieces of non-dissolvedcapsule from travelling with the urine flow and temporarily blockingpossible valves or siphoning system. The term “measurement chamber” maybe used as a general term denoting the whole chamber comprising a firstportion 115, i.e., an inlet upstream portion or “atrium”, a secondportion 120 midstream which is the actual measurement portion of themeasurement chamber presenting important surfaces for the sensors.Further downstream is provided a third portion 130, 140 providing theself-emptying siphoning arrangement 130 and outlet piping 140. To beable to treat the surfaces of the second portion 120 and the thirdportion 130 with oil from the capsule, the capsule is provided in thefirst portion 115, the atrium. The grate 110 is arranged between theatrium 115 and the second portion 120 of the measurement chamber 101.

Oil

The oil is a purpose selected oil. Viscosity may be at most 600centiStoke (cSt, mm²/s). Viscosity is preferably in the interval of 200to 600 centiStoke (cSt, mm²/s). Viscosity is more preferred in theinterval of 300 to 400 centiStoke (cSt, mm²/s). Viscosity is even morepreferred in the interval of 345 to 355 centiStoke (cSt, mm²/s). An oilhaving a viscosity of at most 600 cSt or within these intervals isspread on top of urine and forms a layer of the oil on top of the urine.The oil is spread over the surface of the urine. An oil having suchviscosities is spread on top of the urine, is brought in contact withthe inner surfaces of the urine measurement system and is applied to theinner surfaces of the urine measurement system in the way describedabove. A too high viscosity will result in that oil not is spread overthe surface of urine and thereby not is brought in contact with innersurfaces of a urine measurement system and nor is applied to innersurfaces of a urine measurement system. Instead an oil having a too highviscosity will accumulate and form a clump.

The oil is preferably of a grade approved for medical use. It ispreferably an oil comprising as a major constituent an oil preferablyselected from the group of silicone fluids or mineral oils or from acombination thereof.

The silicon oil is preferably selected from polydimethylsiloxanes,polymethylphenylsiloxanes, polydipropylsiloxanes, andpolyphenylsiloxanes. More preferably the silicon oil is selected frompolydimethylsiloxanes. More preferred is an oil composition selectedfrom the group of linear polydimethylsiloxanes, such as for exampleSILBIONE oil 70047 V 350 from BluestarSilicones—www.blustarsilicones.com. Most preferred is an oil comprising90-100% silicone oil of viscosity about 350 cSt. The oil may be free ofadditive, or may comprise one or more additives.

The volume of oil provided in the capsule to achieve the described hasbeen tested and effect is achieved with a volume of 0.5 ml of oil.

The capacitive sensors are not influenced, or being influenced onlynegligible by the oil mixture.

Oil Treatment

The inventors have also generalised that the purpose selected oildisclosed above may be applied to urine handling system surfaces usingother methods than by capsule. Thus a specific use of the oil is made anobject of the present invention;

It is disclosed the use of a compound X in the application Y, whereinthe compound X is an oil mixture comprising 90-100% of an oil selectedfrom the group consisting of silicone fluids and mineral oils or amixture thereof, and having a viscosity of at most 600 cSt, preferablywithin the interval of 300 to 400 cSt, more preferred within theinterval of 300 to 400 cSt, even more preferred 345 to 355 cSt, and mostpreferred about 350 cSt, and wherein the application Y is the treatmentof luminal surfaces of a urine handling system or a urine measurementsystem. With the term “treatment” is here meant an activity wherein theoil is applied to the surface in question regardless of the method ofdistribution of the oil into the luminal space of the urine handlingsystem. Preferred methods include pouring oil into the luminal space,spraying, painting, immersion, soaking, releasing, and distribution withthe aid of a watery fluid. The watery fluid may be urine. In particularis distribution involving release of the oil mixture from a capsule asdescribed above preferred and more preferred is distribution from such acapsule where the released oil mixture is transported into the luminalspace with the urine. Regardless of the method of distribution of theoil mixture into the luminal space, the oil mixture may be applied tothe luminal surfaces of the urine handling system by self-priming asdescribed above.

In the present invention the oil treatment as described is taught assingle step of treatment of the surfaces for increased operational time.The oil is a non-complex compound involving no other substance, like anantimicrobial agent, such as for example chlorhexidine. It is anadvantage that no other substance, like an antimicrobial agent, such asfor example chlorhexidine, is needed. The oil mixture may advantageouslybe void of such antimicrobial substance. This is also true regarding theoil mixture when released by capsule.

Material of Measurement Chamber

The material of the measurement chamber is preferably a polymer ofmedical equipment grade. More preferred the material of the measurementchamber is a polymer of medical equipment grade, wherein the polymerexhibits a lipophilic surface. Most preferred the material of themeasurement chamber is polypropylene. Tests have shown that lipophilicmaterial keep the oil at the chamber surface, in contrast to alipophobic material which will repel the oil. Thus, with a lipophobicmaterial the oil would be washed away by the urine rather quickly bytime.

Examples/Tests

The following table illustrates a combination of capsule material, oil,and measurement chamber material.

Prolonged Capsule Chamber operational EXAMPLE material Oil/viscositymaterial time (%) EX A hydroxypropyl Silicone/ poly- 480 to 840methylcellulose 350 cSt propylene

A series of tests with a urine measurement system having an electronicmeasurement system and a self-emptying siphoning arrangement have beenperformed. The time until surface degradation in the form of biofilmformation were determined by measuring the time until either theelectronic measurement signal is unsatisfactory or disappears or untilthe function of the self-emptying siphoning arrangement isunsatisfactory or ceases. The material of the measurement chamber of themeasurement system is polypropylene. Tests were performed with andwithout oil. In tests involving an oil, the oil was supplied by means ofa capsule. The oil as well as the material of the capsule wall isspecified in the table above. Two different samples of urine were testedand the results are presented below.

Time until surface degradation in hours Test number Urine sample Withoil Without oil 1 1 479 2 1 68 3 1 68 4 1 57 5 1 74 6 2 336 7 2 70 8 258For urine sample 1 the operational time until surface degradationincreased from 57-74 hours without oil to 479 hours when having an oilpresent, which corresponds to an prolonged operational time of 650-840%.For urine sample 2 the operational time until surface degradationincreased from 58-70 hours without oil to 336 hours when having an oilpresent, which corresponds to an prolonged operational time of 480-580%.

1. A urine handling system capsule (105) for releasing an oil mixture inthe lumen of a urine handling system, the capsule (105) comprising acapsule wall defining a space filled with an oil mixture, wherein theoil mixture comprises 90-100% of an oil selected from the groupconsisting of silicone fluids and mineral oils or a mixture thereof, andhaving a viscosity of at most 600 cSt, and wherein the capsule wall ismade of a water-soluble material.
 2. The capsule (105) according toclaim 1, wherein the water-soluble material is selected from the groupconsisting of hydroxypropyl methylcellulose and polyvinyl alcohol (PVOH)or a mixture thereof.
 3. The capsule (105) according to claim 1 or 2,wherein the oil mixture is selected from the group of silicone fluids.4. The capsule according to claim 3, wherein the oil mixture is selectedfrom the group of linear polydimethylsiloxanes.
 5. The capsule accordingto any one of claims 1-4, wherein the viscosity of the oil is in theinterval of 200 to 600 cSt, such as in the interval of 300 to 400 cSt,such as in the interval of 345 to 355 cSt, such as about
 350. 6. A urinemeasurement system (101) comprising a urine measurement chamber (101),wherein the urine measurement system comprises an electronic measurementsystem comprising electrodes arranged outside said measurement chamber(101) to measure changing capacitance values as urine level inside thechamber (101) increases and/or the urine measurement chamber (101)comprises a self-emptying siphoning arrangement (130) arranged to emptyitself by means of siphoning technique, wherein an oil mixture isarranged in the luminal space of the urine measurement system, whereinthe oil mixture comprises 90-100% of an oil selected from the groupconsisting of silicone fluids and mineral oils or a mixture thereof, andhaving a viscosity of at most 600 cSt.
 7. A urine measurement systemaccording to claim 6, wherein the viscosity of the oil is in theinterval of 200 to 600 cSt, such as in the interval of 300 to 400 cSt,such as in the interval of 345 to 355 cSt, such as about
 350. 8. A urinemeasurement system according to claim 6 or 7, wherein a capsule (105)according to any of claims 1 to 5 is arranged in the luminal space ofthe measurement system.
 9. The urine measurement system according toclaim 8, wherein the capsule (105) is arranged upstream of themeasurement chamber (101) or in an upstream portion of the measurementchamber (101) and is prevented from entering the measurement chamber bya grate (110).
 10. The urine measurement system according to claim 9,wherein the grate (110) is made of a metal or polymer material.
 11. Theurine measurement system according to any one of claims 6-10, whereinthe material of the measurement chamber is selected from a groupconsisting of polymer materials.
 12. The urine measurement systemaccording to any one of claims 6-10, wherein the material of themeasurement chamber is selected from a group consisting of glassmaterials.
 13. The urine measurement system according to any one ofclaims 6-12, wherein the material of the measurement chamber is selectedfrom a group of materials having lipophilic properties.
 14. A method forinhibiting impairment of functionality and measurement accuracy in aurine measurement system having inner surfaces coming into contact withurine, the method comprising the following step(s): applying an oilmixture to the inner surfaces of the urine measurement system byself-priming with the aid of the urine.
 15. The method according toclaim 14, wherein the method comprises the step spreading the oilmixture on top of the urine.
 16. The method according to claim 14 or 15,wherein, the oil mixture is applied to the inner surfaces of the urinemeasurement system when the level of urine in the urine measurementsystem increases.
 17. The method according to any one of the claims14-16, wherein the urine takes with it the oil mixture when the level ofurine in the urine measurement system increases during filling of themeasurement system and thereby the oil mixture is brought in contactwith and adheres to the inner surfaces.
 18. The method according to anyone of claims 14-17, wherein the oil mixture comprises 90-100% of an oilselected from a group consisting of silicone fluids, and mineral oils,or from a mixture thereof.
 19. The method according to any one of claims14-18, wherein the oil has a viscosity of at most 600 cSt, such as inthe interval of 200 to 600 cSt, such as in the interval of 300 to 400cSt, such as in the interval of 345 to 355 cSt, such as of about 350cSt.
 20. The method according to any one of claims 14-19, wherein theoil mixture is applied by connecting a patient's urinary catheter withthe urine measurement system of any of claims 6 to 13 provided with thecapsule of any of claims 1 to
 5. 21. Use of an oil mixture in treatmentof luminal surfaces of a urine handling system, wherein the oil mixturecomprises 90-100% of an oil selected from the group consisting ofsilicone fluids and mineral oils or a mixture thereof, and having aviscosity of at most 600 cSt.
 22. The use according to claim 21, whereinthe viscosity is in the interval of 200 to 600 cSt, such as 300 to 400cSt, such as 345 to 355 cSt, such as about
 350. 23. The use according toclaim 21 or 22, wherein the oil mixture is void of antimicrobial agent.